JPS63141799A - Transfer method of dyestuff - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for transferring cyan vinyl dyes from their supports to paper coated with synthetic resins by sublimation or vaporization with a thermal head.

In the sublimation transfer method, a transfer paper containing a sublimable dye, optionally together with a binder, on a support is heated from the back side using a thermal head with a short thermal shock. In this case, the dyestuffs starve or evaporate onto the absorption medium. An essential advantage of this method is that control of the amount of dye transferred (and thus color blurring) can be easily achieved by adjusting the energy applied to the thermal head.

Generally, color representation is performed using six subtractive primary colors: yellow, red, and blue (and sometimes black). In order to enable optimal color display, it is necessary that the dyes used have the following properties:

Also, sublimation is easy to vaporize (generally, this requirement is most difficult to meet in the case of cyan dyes).

High thermal and photochemical stability and resistance to moisture and chemicals.

Must have appropriate tone for mixing basic colors.

Having a high molecular absorption constant.

Scales that can be easily obtained industrially.

Many of the known thermal transfer dyes do not meet these requirements to a sufficient extent.

Various dyes are known for this purpose according to the state of the art. For example, JP-A-60-229786 describes dicyano- and tricyanovinyl dyes, in which either the dicyano- or tricyanovinyl group is bonded to a dialkylaminophenyl group.

The object of the present invention is to easily sublimate or volatilize under the conditions of use of the thermal head and not cause thermal and photochemical decomposition.
The objective was to develop a method for transferring dyes using dyes that can be processed into printing inks and that satisfy the color requirements.

In addition, this dye must be easily available industrially.

The present invention provides that the following formulas CRI and R2 may be the same or different, and are independently substituted with a hydrogen atom, a C0-C4-alkyl group (a fluorine atom, a chlorine atom, a bromine atom, or a 01-C4-alkoxy group). 5- or 6-membered saturated heterocyclic residue, R3 is a hydrogen atom ,01~C4
-Alkyl group, benzyl group, phenyl group, C1-C,-
Flucoxyphenyl group, C, ~C4-dialkylaminophenyl group, halogen atom or furyl group or chenyl group, each optionally substituted with 01-C4-alkyl group, fluorine atom, chlorine atom or bromine atom, R4 is hydrogen atom or a cyan group, and R5 is a cyano group or a group C
0OR'(R' is a C,~C4-alkyl group, which is a fluorine atom, chlorine atom, bromine atom, hydroxyl group, 01~C4-
(optionally substituted with alkoxy, C2-C7-cycloalkyl or phenyl) or C6-C7-
cycloalkyl group] is present, by sublimation or vaporization using a thermal head.
This method involves transferring dye to paper coated with synthetic resin.

Examples of R1 and R2 in formula I are hydrogen atoms as well as the following groups: Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary butyl, fluoroethyl, chloromethyl, chloromethyl, trifluoromethyl, 2-fluoroethyl, 2-40 ethyl, 2-bromoethyl, pentafluoroethyl, 2-10 Roux 1.
1.2.2-tetrafluoroethyl, nonafluorobutyl; 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl, 2-sec-butoxyethyl, 2 -Methoxypropyl, 1-methoxypropyl-2,2-methoxybutyl, 2-ethoxybutyl, 4-methoxybutyl, 4-1
propoxybutyl; ethynyl, propene-(2)-1
-yl, buten-(2)-1-yl, 2-methylpropen-(2)-1-yl; phenyl; benzyl or cyclohexyl.

R1 and R2 may also be combined with a nitrogen atom to form, for example, the following heterocyclic residue. Pyrrolidino, piperidino, morpholino, N-methylpiperazino, N-ethylpiperazino, N-propylpiperazino, N-isopropylpiperazino, N-butylpiperazino, N-isobutylpiperazino or N-secondary butylpiperazino.

Examples of R3 in formula I are hydrogen atoms as well as the following groups or atoms: Methyl, ethyl, propyl, isopropyl, butyl,
Isobutyl, secondary butyl, tertiary butyl; benzyl; phenyl: 2-methoxyphenyl, 4-methoxyphenyl,
2-ethoxyphenyl, 4-ethoxyphenyl, 4-7
'Ropoxyphenyl, 4-isopropoxyphenyl, 4
-butoxyphenyl, 4-inbutoxyphenyl, 4-
Secondary butoxyphenyl, 4-tertiary butoxyphenyl, 4
-Pentyloxyphenyl, 4-isopentyloxyphenyl, 4-hexyloxyphenyl; 2-dimethylaminophenyl, 4-dimethylaminophenyl, 4-diethylaminophenyl, 4-dipropylaminophenyl,
4-diisopropylaminophenyl, 4-dibutylaminophenyl, 4-(N-methyl-N-ditylamino)-
Phenyl; F, C1, Br; furyl-2,5-methylfuryl-2,5-ethylfuryl-2,5-propylfuryl-2,5-isopropyfuryl-2,5-butylfuryl-2,2,5- Dimethylfuryl-3,2,4,5-trimethylfuryl-3; 5-fluorofuryl-2,5-chlorfuryl-2,5-bromofuryl-2; chenyl-2,
5-methylchenyl-2,5-ethylchenyl-2,5
-7'ropyruchenyl-2,2,5-dimethylchenyl-3,5-fluororchenyl-2,5-10ruthenyl-2 or 5-bromochenyl-2° R4 in formula I is H or CN.

The R5 column of formula I is the following group: Cyano; methoxycarbonyl, ethoxycarbonyl, propoquine carbonyl,
Isopropoxycarbonyl, butoxycarbonyl, secondary butoxycarbonyl, tertiary butoxycarbonyl, fluoromethoxycarbonyl, chlormethoxycarbonyl, chloromethoxycarbonyl, trifluoromethoxycarbonyl, 2-fluoroethoxycarbonyl, 2-chloroethoxycarbonyl, 2 -bromomethoxycarbonyl, pentafluoroethoxycarbonyl, 2-chloro-1
, 1,2,2-tetrafluoroethoxycarbonyl, nonafluorobutoxycarbonyl; 2-hydroxyethoxycarbonyl, 2-hydroxypropoxycarbonyl,
6-hydroxypropoxycarbonyl, 2-hydroxybutoxycarbonyl, 4-hydroxybutoxycarbonyl; 2-methoxyethoxycarbonyl, 2-ethoxyethoxycarbonyl, 2-propoxyethoxycarbonyl, 2-impropoxyethoxycarbonyl, 2-butoxyethoxycarbonyl, 2 -Second-class butoxyethoxycarbonyl, 2-methoxypropoxycarbonyl/L/hole,
3-methoxypropoxycarbonyl, 1-methoxypropoxy-2-carbonyl, 2-methoxybutoxycarbonyl, 2-ethoxybutoxycarbonyl, 4-methoxybutoxycarbonyl, 4-isopropoxybutoxycarbonyl; cyclopentylmethoxycarbonyl, cyclohexylmethoxycarbonyl, cycloheptyl The reaction is preferably carried out using a support containing methoxycarbonyl, 2-cyclohexylethoxycarbonyl, benzyloxycarbonyl, 2-phenylethoxycarbonyl; cyclopentyloxycarbonyl, cyclohexyloxycarbonyl or cycloheptyloxycarbonyl.

In this formula, R1 and R2 are hydrogen atoms, C
3-C1-alkyl group, benzyl group, phenyl group, or together with a nitrogen atom, means a 5- or 6-membered saturated heterocyclic residue, R3 is a hydrogen atom, a C1-C4 furkyl group, a benzyl group, a phenyl group, a 4-(C,~C4-alkoxy)-phenyl group, a 4-(C,~C4-dialkylamino)-phenyl group, or a furyl or chenyl group optionally substituted with a methyl group or a chlorine atom, respectively; means.

Dyes of the formula I are known per se or can be prepared by known methods. For example, the dye of formula (3) in which R4 is a hydrogen atom can be prepared by subjecting an unsubstituted thiazole at the 5-position of the corresponding ring to Vielsmeier formylation, and converting the resulting 5-formylthiazole to malondinitrile or the corresponding cyanide. Obtained by reaction with acetic acid ester.

Other production methods are described in DE-A-3227329 and Annalen del Hemi-250% (1889) 2
It is described on page 65.

Tricyanovinyl dye (R4=cyano group) is J, A,
C, Vol. 8, Vol. 80 (1958), p. 2806, by reacting the corresponding thiazole derivative with tetracyanoethylene.

Compared to the dyes used in known methods, the dyes transferred by the method of the invention generally have better sublimation properties, higher lightfastness, higher resistance to chemicals and lower re-sublimation from paper. Excellent in nature.

To prepare the dye support required for the process, the dye is processed into a printing ink in a suitable solvent, such as chlorobenzole or isobutanol, together with a binder. It contains the dye in dissolved or dispersed form. This printing ink is applied onto an inert support using a doctor knife,
Allow this stain to air dry.

As binder, for example ethylcellulose, polysulfone or polyethersulfone is used. Inert carriers used are, for example, tissue paper, blotting paper, parchment paper or synthetic resin sheets with good thermal stability, such as polyesters, polyamides or polyimides, optionally coated with metal.

The thickness of the support is preferably 6 to 30 μm. Further support materials, binders and solvents for producing printing inks which are suitable for the process according to the invention are disclosed in DE-A-35245
It is described in the specification of No. 19.

As dye-receiving layer, in principle all heat-stable synthetic resin layers having an affinity for the dyes to be transferred, such as polyester, can be used.

Transfer is effected by a thermal head which provides sufficient heat transfer to transfer the dye in less than a tenth of a second.

The invention is illustrated in more detail by the following examples.

In order to test the transferability of dyes quantitatively and in a simple manner, thermal transfer is carried out using a wide surface heated press instead of a thermal head. Additionally, binders are omitted in the production of test dye supports.

A) General guidelines for applying dyes to the support: 1 g of ethylene glycol, 11 of a dispersant based on a condensation product from phenol, formaldehyde and sodium bisulfite, Z5 water! ! 0.5 g of the dye of the formula
Shake until below μm (requires 8-12 hours depending on the dye). The glass bulbs are then sieved and the resulting dye dispersion, optionally diluted to 2 volumes with water, is applied to paper with a 6 μm doctor knife and air-dried.

B) Sublimation or vaporization test: The paper coated with the dye under test (donor) is pressed onto a polyester sheet (receiver) having a thickness of 80 μm on the side where the dye layer is present. The pressed body (donor/receiver) is then covered with aluminum foil and heated for 60 seconds between two heating plates.

The amount of dye transferred to the polyester sheet is measured photometrically.

When the logarithm of the absorbance A of a colored polyester sheet measured at various temperatures is plotted against the corresponding opposite absolute temperature, a straight line is obtained, and from its slope the activation energy ΔET for the transfer experiment is calculated by the following formula: Ru.

*For complete characterization, the temperature T ('C) is further extracted from the diagram, giving a value of 1 for the absorbance A of the colored polyester sheet.

A dye of the following formula shown in Table 1 is processed according to (A), and a support coated with the obtained dye is tested for sublimability according to (B).

The table shows the color tones obtained, as well as the heat transfer factors T and Δ.

Table 1 H3 Similarly, the following formula shown in Table 2 dye is transferred.

Table 2 Dye x y
Color tone 2H5

Claims (1)

[Claims] 1. The following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) [R^1 and R^2 may be the same or different, and independently represent a hydrogen atom, C_1 to C_4- Alkyl group (fluorine atom, chlorine atom, bromine atom or C_1-C
_Optionally substituted with 4-alkoxy group), C
_2~C_4-alkenyl group, benzyl group, phenyl group, cyclohexyl group, or together with a nitrogen atom, means one 5- or 6-membered saturated heterocyclic residue, R^3 is a hydrogen atom, C_1~ C_4-alkyl group, benzyl group,
phenyl group, C_1-C_6-alkoxyphenyl group,
C_1-C_4-dialkylaminophenyl group, a halogen atom or a furyl group or thienyl group each optionally substituted with a C_1-C_4-alkyl group, fluorine atom, chlorine atom or bromine atom, R^4 is a hydrogen atom or a cyano group , and R^5 is a cyano group or a group COOR^6
(R^6 is a C_1-C_4-alkyl group, which is a fluorine atom, chlorine atom, bromine atom, hydroxyl group, C_1-C_4-
(optionally substituted with alkoxy group, C_5-C_7-cycloalkyl group or phenyl group) or C_5-
A method of transferring a dye from a support on which a dye represented by C_7-cycloalkyl group is present to paper coated with a synthetic resin by sublimation or vaporization using a thermal head. 2. R^1 and R^2 are hydrogen atoms, C_
1-C_4-alkyl group, benzyl group, phenyl group, or together with a nitrogen atom, means a 5- or 6-membered saturated heterocyclic residue, where R^3 is a hydrogen atom, C_1-C_4-alkyl group, benzyl group, phenyl group, 4-(C_1 to C_4
-alkoxy)-phenyl group, 4-(C_1 to C_4-
2. Process according to claim 1, characterized in that it means a furyl or thienyl group, which may be substituted by a methyl group or a chlorine atom, respectively.